Desertification, caused by land degradation as opposed to the immediate creation of classical deserts, is of prime concern in the 21st century. As a result of human activities and climate change, the land loses its proper hydrologic function and biological productivity. Desertification affects 33 % of the earth's surface and over a billion people. Fire-related desertification has a number of environmental, social, and economic consequences. The two key environmental consequences are soil erosion and non-native plant invasions. Erosion after wildland fires can be in the range of

The worldwide phenomenon of shrub encroachment in grass-dominated dryland ecosystems is commonly associated with desertification. Studies of the purported desertification effects associated with shrub encroachment are often restricted to relatively few study areas, and document a narrow range of possible impacts upon biota and ecosystem processes.

An assessment of sensitivity to land degradation has been carried out in the Extremadura region, SW Spain, by means of a modelling approach developed by the European Commission funded MEDALUS project (Mediterranean Desertification and Land Use) which identifies such areas on the basis of an index (Environmentally Sensitive Area index, ESA index) that incorporates data on environmental quality (climate, vegetation, soil) as well as anthropogenic factors (management).

Established in 1994, the United Nations to Combat Desertification (UNCCD) is the sole legally binding international agreement linking environment and development to sustainable land management. The Convention addresses specifically the arid, semi-arid and dry sub-humid areas, known as the drylands, where some of the most vulnerable ecosystems and peoples can be found.

Climate change presents a profound challenge to food security and development. Negative impacts from climate change are likely to be greatest in regions that are currently food insecure and may even be significant in those regions that have made large gains in reducing food insecurity over the past half-century. Adaptation in the agricultural sector is being given a high priority within this effort because of the inherent sensitivity of food production to climate and the strong inter-linkages that exist between climate, agriculture, and economic growth and development.

Human activities have resulted in unprecedented phenomena and severe impacts for the 21st century such as land degradation, natural resources scarcity, climate change, and a rapid decline in biodiversity. These alterations engender secondary effects such as political conflicts, disputes over resources, social disruptions and sudden shocks of catastrophic weather events which are becoming more frequent in critical regions of the world, particularly in drylands; and exacerbate threats for human, national and international security.

The Country Environmental Analysis (CEA) for Timor-Leste identifies environmental priorities through a systematic review of environmental issues in natural resources management and environmental health in the context of the country's economic development and environmental institutions. Lack of data has been the main limitation in presenting a more rigorous analysis. Nevertheless, the report builds on the best available secondary data, presents new data on the country's wealth composition, and derives new results on the costs of water and air pollution.

A localização geográfica de Moçambique nos trópicos e subtrópicos, faz com que ele seja vulnerável a eventos extremos de origem meteorológica tais como secas, cheias e ciclones tropicais e de origem geológica como é o caso de sismos e tsunamis. Dentre as diversas zonas do país, as áridas, semi-áridas e sub-húmidas secas são as mais vulneráveis, devido à degradação da terra caracterizada por perda persistente de productividade de vegetação, solos e pastagens e exacerbada pelo seu uso inapropriado (UNDP, 1992). As regiões sul e parte do centro do país são as mais afectadas pela seca.

In the not so long history of humankind, our ancestors too often fought for land and water. Those days have returned.

En la no tan larga historia de la Humanidad, nuestros antepasados han luchado con demasiada frecuencia por la tierra y el agua. Aquellos tiempos están nuevamente de actualidad.

This is a brief for Policy Makers titled "From Land Degradation to Land Health"

C'est une adresse aux Décideurs "De la dégradation à la santé des sols"